User`s manual

184 Chapter 6
O:\Manuals\E6380A_Progguid\Book\Advoper.fm
Advanced Operations
Instrument Initialization
Device Clear (DCL) HP-IB Bus Command
The Device Clear (DCL) Reset is accomplished by sending the DCL
message to the Test Set through the HP-IB bus.
The DCL command clears the Input Buffer and Output Queue, clears
any commands in process, puts the Test Set into the Operation
Complete idle state, and prepares the Test Set to receive new
commands. The DCL bus command does not change any settings or
stored data (except as noted previously), interrupt front panel I/O,
interrupt any Test Set operation in progress (except as noted
previously), or change the contents of the Status Byte Register (other
than clearing the MAV bit as a consequence of clearing the Output
Queue).
The DCL bus command has no effect on the I/O CONFIGURE,
INSTRUMENT CONFIGURE, PRINTER CONFIGURE, SOFTWARE
MENU, or TESTS (Execution Conditions, External Devices, Printer
Setup) screens.
Other operational characteristics are also affected by the DCL bus
command as follows:
• The Power-up self-test diagnostics are not performed.
• The HP-IB interface is not reset (any pending Service Request is not
cleared)
• Measurement triggering is not affected.
• Calibration data is not affected.
• The Contents of the SAVE/RECALL registers are not affected.
• All Enable registers are unaffected: Service Request, Standard
Event, Hardware #1, Hardware #2, Operation, Calibration, and
Questionable Data/Signal.
• All Negative Transition Filter registers are unaffected: Hardware
#1, Hardware #2, Operation, Calibration, and Questionable
Data/Signal.
• All Positive Transition Filter registers are unaffected: Hardware #1,
Hardware #2, Operation, Calibration, and Questionable
Data/Signal.
• The contents of the RAM are unaffected.
• The contents of the Error Queue are unaffected.
• The state of the Test Set’s display screen is unaffected.